Surveying system

ABSTRACT

An automatic surveying system is provided that comprises a surveying device, a collinear-line calculating processor, a sighting direction control processor, and an object-point searching processor. The collinear line calculating processor obtains a collinear line for an arbitrarily designated point on a schematic image of which the positional relation to the surveying device is known. The sighting direction control processor controls the surveying device to sight along the collinear line. The object point searching processor searches for an object point where the position of the object point can be determined as a point on the collinear line. This is executed by measuring the sighting direction with the surveying device while carrying out the sighting direction control process. Further, a position obtained by the object point searching processor coincides with an object point that corresponds to the designated point.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a surveying system. Inparticular, it relates to a surveying instrument or system, including atotal station, an electronic tacheometer, or the like, that is able tomeasure an angle and a distance relating to a measurement point.

[0003] 2. Description of the Related Art

[0004] Generally, a surveying operation requires at least two persons.Namely, one holds a target, such as a prism or the like, at ameasurement point, while the other person operates a surveyinginstrument. In the surveying operation, in order to obtain measurementdata for a plurality of measurement points, the person with the targetshould move to each of the measurement points, and the other personshould sight the surveying instrument to the target, each time thetarget moves to a measurement point. Therefore, the conventionalsurveying operation is quite cumbersome and requires at least two peopleand a lot of time, so it is inefficient and expensive. Recently, anon-prism-type surveying instrument, which requires no target, has beendeveloped. With the non-prism-type surveying instrument, the person whocarries the target can be excluded and the surveying can be carried outby a single person who operates the surveying instrument, so that theefficiency of the surveying operation is improved. However, even whenusing the non-prism-type surveying instrument, the operator should stillcarry out sighting operations for each of the measurement points. Thisbecomes extremely cumbersome and requires time particularly when thenumber of measurement points is large, such as when estimating thevolume of a basin or hollow ground to be buried.

SUMMARY OF THE INVENTION

[0005] Therefore, an object of the present invention is to improveefficiency of the surveying operation. More particularly, the inventionaims to cooperate measurement information obtained by a surveyinginstrument and image information of a surveying area which is obtainedby a camera, simply and efficiently, thereby improving efficiency.

[0006] According to the present invention, a surveying system isprovided. The system comprises a surveying device, a collinear-linecalculating processor, a sighting direction control processor, and anobject-point searching processor.

[0007] The collinear-line calculating processor obtains a collinear linewhich provides a collinear condition for an arbitrarily designated pointon a schematic image of which the positional relation to the surveyingdevice is known. The sighting direction control processor controls thesighting direction of the surveying device to move along the collinearline. The object-point searching processor searches for an object pointthat can be determined as a point on the collinear line by measuring thesighting direction with the surveying device, while carrying out thesighting direction control procedure. Further, the position obtained bythe object point searching processor coincides with an object point thatcorresponds to the designated point on the schematic image.

[0008] Further according to the present invention, an automaticsurveying system is provided that comprises a position relationcalculating processor, a correspondence establishing processor, an inputdevice, and a sighting direction control processor.

[0009] The position relation calculating processor calculates apositional relation between a coordinate system to which measurementinformation of a measurement point refers and a schematic image of asurveying field, which includes the measurement point. Thecorrespondence establishing processor establishes correspondence betweenmeasurement information of the measurement point and positioninformation of a point corresponding to the measurement point on theschematic image with respect to the above positional relation. The inputdevice enables a designation of a measurement point on the schematicimage. The sighting direction control processor controls a sightingdirection of a surveying device in accordance with the position of thedesignated measurement point on the schematic image, which is designatedby using the input device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The objects and advantages of the present invention will bebetter understood from the following description, with reference to theaccompanying drawings in which:

[0011]FIG. 1 is a block diagram showing a general electricalconstruction of a surveying system for an embodiment of the presentinvention;

[0012]FIG. 2 is a flowchart of the survey operation processes in thesurveying system;

[0013]FIG. 3 schematically illustrates an arrangement of the surveyinginstrument and the camera;

[0014]FIG. 4 schematically illustrates the relations between the controlpoints and the corresponding image points on the imaging surface S;

[0015]FIG. 5 is a flowchart of the space resection program thatcalculates exterior and inner orientation parameters;

[0016]FIG. 6 schematically illustrates an example of the schematic imageindicated on the display;

[0017]FIG. 7 schematically illustrates the principle of an automaticsurveying operation in the present embodiment;

[0018]FIG. 8 is a flowchart of the automatic surveying operation in thepresent embodiment;

[0019]FIG. 9 is a flowchart of an object point searching process whichis carried out in Step S303 of FIG. 8;

[0020]FIG. 10 schematically illustrates the relation between thesighting telescope of the surveying instrument and the surveyingcoordinates;

[0021]FIG. 11 is a flowchart of the unit collinear vector calculatingprocess;

[0022]FIG. 12 is a flowchart of the surveying operation for an alternateembodiment; and

[0023]FIG. 13 is a flowchart of the surveying operation for an alternateembodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The present invention is described below with reference to theembodiments shown in the drawings.

[0025]FIG. 1 is a block diagram showing a general electricalconstruction of an embodiment of the present invention, which includes asurveying instrument and a camera.

[0026] A surveying instrument 10 of the present embodiment may be atotal station or the like that comprises a sighting telescope 17. Thesighting telescope 17 has a horizontal axis Lh for measuring an altitudeθp, and a vertical axis Lp for measuring a horizontal angle θh. Namely,the sighting telescope 17 is vertically rotatable about the horizontalaxis Lh and horizontally rotatable about the vertical axis Lp. Thehorizontal axis Lh and the vertical axis Lp intersect at point O_(S)(referred to as the sighting origin O_(S) in the following) at a rightangle. The optical axis LN_(O) (or collimation axis) of the sightingtelescope 17 passes through the sighting origin O_(S). The optical axisLN_(O) is bifurcated by a half-mirror 18, so that one of the bifurcatedoptical axes reaches the eyepiece lens and the other reaches thedistance measurement component 11.

[0027] The distance measurement component 11 detects an oblique distanceto a measurement point (which is sighted) by using a phase modulationmeasurement method, a pulse radar method, or the like, while an anglemeasurement/control component 12 detects a vertical angle θp and ahorizontal angle θh. Further, the sighting telescope 17 can be rotatedabout each of the horizontal and vertical axes Lh and Lp by using anactuator (not shown), such as a stepping motor. This motor drivenrotation of the sighting telescope 17 is controlled by the anglemeasurement/control component 12.

[0028] The distance measurement component 11 and the anglemeasurement/control component 12 are connected to a system controlcircuit 13, whereby they are controlled by signals from the systemcontrol circuit 13. For example, the distance measurement component 11detects a distance in accordance with signals from the system controlcircuit 13, and outputs the detected data or measurement data to thesystem control circuit 13. On the other hand, the anglemeasurement/control component 12 continuously detects angles at aregular timing and outputs the detected data or measurement data to thesystem control circuit 13 when it is required. Further, the anglemeasurement/control component 12 controls the rotational movement of thesighting telescope 17 about the horizontal and vertical axes Lh and Lpby driving the stepping motor. The detected data, such as an obliquedistance, horizontal angle, and vertical angle, are processed in thesystem control circuit 13. The system control circuit 13 is alsoconnected to a switch group 14, a display 15 (ex. LCD), an interfacecircuit 16, and so on.

[0029] A computer 40, such as a notebook sized personal computer, may beconnected to the interface circuit 16 through an interface cable.Namely, the surveying instrument 10 can transmit measurement data to thecomputer 40 via the interface cable. Further, the surveying instrument10 can be controlled by control signals from the computer 40. Forexample, a sighting operation of the sighting telescope 17, to anarbitrary direction (horizontal angle θh and vertical angle θp), may becontrolled by the computer 40. Note that, the interface circuit 16 isalso available for other peripheral devices, such as a data collector,and the like, which are not shown.

[0030] The computer 40 is generally comprised of a CPU 41, a recordingmedium 42, input devices including a mouse 43 and a keyboard 44, adisplay (image indicating device) 45, and an interface circuit 46.Examples of the recording medium 42 are a hard disk, DVD, MO, and ICcard. Further, the display 45 includes an LCD, CRT, and so on. Asdescribed above, the interface circuit 46 is connected to the interfacecircuit 16 of the surveying instrument 10 via the interface. Further,the interface circuit 46 can be connected to a digital still camera 20.Namely, an image captured by the digital still camera 20 is transmittedto the computer 40 as digital image data and stored in the recordingmedium 42 via the interface circuit 46, for example.

[0031] With reference to FIG. 1, FIG. 2, and FIG. 3, a single photographorientation process in the surveying system of the present embodimentwill be described. FIG. 2 is a flowchart of the single photographorientation process in the surveying system of the present embodiment.FIG. 3 schematically illustrates an arrangement of the surveyinginstrument and the camera in the surveying system of the presentembodiment.

[0032] In Step 101, an operator takes a picture or image around thesurveying area with the digital still camera (DSC) 20. Further, theobtained digital image data are transmitted to the computer 40 via theinterface cable, and then stored in the recording medium 42. Note that,a plurality of measurement points, which are to be measured, is includedwithin the above captured digital image (referred to as a schematicimage) taken by the digital still camera 20.

[0033] In Step 102, the schematic image is indicated on the display 45of the computer 40, for example. At this time a plurality of points (orpixels) on the schematic image are selected by the operator by using apointing device such as a mouse 43. Thereby, substantial points in thesubstantial or object space, which correspond to the selected pixels,are designated as control points P_(i) (i=1, 2, . . . , n), where acontrol point is a measurement point that is arbitrarily selected forcalculating the orientation of a schematic image. Further, the positionsof image points P_(i)′ that correspond to each of the control pointsP_(i) are derived as two-dimensional image coordinates(xp_(i)′,yp_(i)′). Note that, the image coordinate system is atwo-dimensional coordinate system of which the origin is at the upperleft corner of the image with the y′-axis being positive in the downwarddirection. Further, the number “n” of control points which are threedimensionally arranged, may be more than 11.

[0034] In Step S103, an oblique distance and the angles (such asvertical and horizontal angle) of each control point P_(i), which areappointed in Step S102, are measured by an operator by using the surveyinstrument 10. Measured values are then fed to the interface circuit 46of the computer 40 via the interface circuit 16. At the CPU 41,three-dimensional coordinates (Xp_(i),Yp_(i),Zp_(i)) for each of thecontrol points P_(i) are calculated in a predetermined surveyingcoordinate system. At this time, the correspondence between thesurveying coordinates (Xp_(i),Yp_(i),Zp_(i)) for each of the controlpoints P_(i) and the image coordinates (xp_(i)′,yp_(i)′) for imagepoints P_(i)′ is determined. Note that, the origin of the surveyingcoordinate system may be taken at the sighting origin O_(s) of thesurveying instrument 10, and the absolute coordinates, includinglatitude and longitude or any type of positioning format defined by therelevant surveying authority, may be adapted to the above surveycoordinates. Further, the surveying coordinates calculation may becarried out in the surveying instrument 10, and later the calculateddata may be sent to the computer 40.

[0035] As will be explained in detail later, exterior orientationparameters for the digital still camera 20, which represent the positionand the inclination of the camera 20 at the moment when the schematicimage was taken, are calculated in Step S104, in accordance with thecorrespondence between the surveying coordinates and the imagecoordinates for each of the control points P_(i), by means of spaceresection. Further, inner orientation parameters for compensating foraberrations from the collinear condition due to lens distortion ordisplacement of the principal point from the image center, may becalculated. Namely, the position or the surveying coordinates(X_(O),Y_(O),Z_(O)) of the origin O_(C) of the three-dimensional cameracoordinate system, which is fixed in the digital still camera 20, andthe rotational angle (ω,φ,κ) about the x-axis, y-axis, and z-axis of thecamera coordinate system, at the time, are derived as exteriororientation parameters. Further, the inner orientation parameters (f:distance from the center of projection for the lens or the principaldistance; D₂,D₄,D₆: second, fourth, and sixth order components of thedistortion; N₁,N₂: unsymmetrical components of distortion; X_(C),Y_(C):displacement of the principal point from the center of the image) areobtained. Thereby, the perspective projection relationship between theimage coordinates and the surveying coordinates is established. Notethat, when the inner orientation parameters are definite for the above(f,D₂,D₄,D₆,N₁,N₂,X_(C),Y_(C)), the number of control points requiredfor calculating the exterior and inner orientation parameters is atleast seven. Among these control points, at least three are required tocalculate the exterior orientation parameters (X_(O),Y_(O),Z_(O),ω,φ,κ)Note that, in the present embodiment, eleven (or more) control pointsare required to calculate the exterior and inner orientations.

[0036] Note that, the camera coordinate system is a left-handedcoordinate system of which the origin O_(C) is located at the center ofthe lens or the center of the projection, and in which the y-axis andz-axis are parallel to each of the s′-axis and t′-axis of the screencoordinate system. Further, the x-axis of the camera coordinate systemis normal to the imaging surface and is oriented to the side opposite tothe imaging surface from the center of the projection. Namely, any pointon the imaging surface is represented by the camera coordinates(−f,y,z). Here, the screen coordinate system is a two-dimensionalcoordinate system of which the origin is defined at the principal pointwith each of the s′-axis and t′-axis arranged in parallel with each ofthe x′-axis and y′-axis, that is, in parallel with each of thehorizontal and vertical lines of the imaging device 21 (see FIG. 4).

[0037] As described above, the single photograph orientation process ofthe present embodiment ends. Note that, the image capturing operation inStep S101 can be excluded and an image taken previously may be used as aschematic image, in place. Further, although the single photographorientation process in the present embodiment is described withreference to the flowchart of FIG. 2, Step S103 may be carried out priorto Steps S101 and S102. Furthermore, previously measured or givenmeasurement data, including the data for the triangulation controlpoint, any type of map data, or geographical data, may be used asmeasurement information for control points.

[0038] With reference to FIG. 4 and FIG. 5, a principle for obtainingthe exterior orientation parameters (position and the inclination) andthe inner orientation parameters of the digital still camera 20, byspace resection (Step S104), will be explained.

[0039]FIG. 4 schematically illustrates the relations between the threecontrol points P₁, P₂, and P₃, and the corresponding image points P₁′,P₂′, and P₃′ on the imaging surface S. FIG. 5 is a flowchart of thespace resection program that calculates exterior orientation parameters(X_(O),Y_(O),Z_(O),ω,φ,κ), which represent the position and theinclination of the digital still camera 20, and inner orientationparameters (f,D₂,D₄,D₆,N₁,N₂,X_(C),X_(C)) which depend on the opticalsystem of the camera 20. For the space resection calculation, a leastsquare method including a successive approximation solution is applied.Note that, although it is acceptable for the number of control points tobe seven or more, here, a case when eleven points are designated for thecontrol points, is explained, as an example. However, for convenience,only three control points P₁, P₂, and P₃ are illustrated in FIG. 4.

[0040] In Step 201, appropriate initial values (X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and (f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)) are given as approximate values for the exteriororientation parameters (X_(O),Y_(O),Z_(O),ω,φ,κ), representing theposition and the inclination of the camera, and the inner orientationparameters (f,D₂,D₄,D₆,N₁,N₂,X_(C),Y_(C)). Then in Step S202,approximate image coordinates (xp_(Gi)′,yp_(Gi)′) of the image pointP_(i)′ (i=1,2, . . . ,11), which correspond to each of the elevencontrol points P_(i), are calculated from the surveying coordinates(Xp_(i),Yp_(i),Zp_(i)) of the respective control points P_(i), by usingthe given exterior orientation parameters(X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and inner orientationparameters (f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)).

[0041] Namely, the coordinates (xp_(i),yp_(i),zp_(i)) of the controlpoints P_(i) (i=1, 2, 3) in the camera coordinate system are derivedfrom coordinates (Xp_(i),Yp_(i),Zp_(i)) of the surveying coordinatesystem by Eq. (1), thereby, approximate camera coordinates(xp_(Gi),yp_(Gi),zp_(Gi)) of the control points P_(i) are obtained bysubstituting the approximate exterior orientation parameters(X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and the surveying coordinates(xp_(i),yp_(i),zp_(i)) of the control points P_(i) into Eq. (1).$\begin{matrix}{\begin{pmatrix}{xp}_{i} \\{yp}_{i} \\{zp}_{i}\end{pmatrix} = {\begin{pmatrix}T_{11} & T_{12} & T_{13} \\T_{21} & T_{22} & T_{23} \\T_{31} & T_{32} & T_{33}\end{pmatrix}\begin{pmatrix}{{Xp}_{i} - X_{0}} \\{{Yp}_{i} - Y_{0}} \\{{Zp}_{i} - Z_{0}}\end{pmatrix}}} & (1)\end{matrix}$

[0042] where {T_(jk)} represents a rotational matrix, and each of theelements T_(jk) are described in the following forms.

T ₁₁=cos φ·cos κ

T ₁₂=cos ω·sin κ+sin ω·sin φ·cos κ

T ₁₃=sin ω·sin κ−cos ω·sin φ·cos κ

T ₂₁=−cos φ·sin κ

T ₂₂=cos ω·cos κ−sin ω·sin φ·sin κ

T ₂₃=sin ω·cos κ+cos ω·sin φ·sin κ

T ₃₁=sin φ

T ₃₂=−sin ω·cos φ

T ₃₃=cos ω·cos φ

[0043] The screen coordinates (sp_(i)′,tp_(i)′) of the image pointP_(i)′ corresponding to the control points P_(i), which have not beingyet been compensated by the inner orientation parameters, are derivedfrom the collinear condition (wherein a control point, the center ofprojection, and the corresponding image point are aligned on the sameline). Therefore, the uncompensated screen coordinates (sp_(i)′,tp_(i)′)are calculated by substituting the exterior orientation parameters(X_(O),Y_(O),Z_(O),ω,φ,κ) and the camera coordinates(xp_(i),yp_(i),zp_(i)) of control points P_(i)into the following Eq.(2). $\begin{matrix}\begin{matrix}{{sp}_{i}^{\prime} = {{{- f}\frac{{yp}_{i}}{{xp}_{i}}} = {{- f}\frac{{T_{21}\left( {{Xp}_{i} - X_{0}} \right)} + {T_{22}\left( {{Yp}_{i} - Y_{0}} \right)} + {T_{23}\left( {{Zp}_{i} - Z_{0}} \right)}}{{T_{11}\left( {{Xp}_{i} - X_{0}} \right)} + {T_{12}\left( {{Yp}_{i} - Y_{0}} \right)} + {T_{13}\left( {{Zp}_{i} - Z_{0}} \right)}}}}} \\{{tp}_{i}^{\prime} = {{{- f}\frac{{zp}_{i}}{{xp}_{i}}} = {{- f}\frac{{T_{31}\left( {{Xp}_{i} - X_{0}} \right)} + {T_{32}\left( {{Yp}_{i} - Y_{0}} \right)} + {T_{33}\left( {{Zp}_{i} - Z_{0}} \right)}}{{T_{11}\left( {{Xp}_{i} - X_{0}} \right)} + {T_{12}\left( {{Yp}_{i} - Y_{0}} \right)} + {T_{13}\left( {{Zp}_{i} - Z_{0}} \right)}}}}}\end{matrix} & (2)\end{matrix}$

[0044] Although, the uncompensated screen coordinates (sp_(i)′,tp_(i)′)are affected by distortion, the effect is compensated for bysubstituting the screen coordinates (sp_(i)′,tp_(i)′) of each imagepoint P_(i)′ and the approximate inner orientation parameters(f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)) into thefollowing Eq. (3). Namely, compensated approximate screen coordinates(scp_(Gi)′,tcp_(Gi)′) are obtained.

R ² =sp _(i)′² +tp _(i)′²

scp _(i) ′=sp _(i)′(1+D ₂ R ² +D ₄ R ⁴ +D ₆ R ⁶)+(R ²+2sp _(i)′²)N ₁+2sp_(i) ′tp _(i) ′N ₂ +X _(C)

tcp _(i) ′=tp _(i)′(1+D ₂ R ² +D ₄ R ⁴ +D ₆ R ⁶)+2sp _(i) ′tp _(i ′N)₁+(R ²+2tp _(i) 40 ²)N ₂ +Y _(C)  (3)

[0045] Further, approximate image coordinates (xp_(Gi)′,yp_(Gi)′) of theimage points P_(i)′ can be derived by substituting the compensatedapproximate screen coordinates (scp_(Gi)′,tcp_(Gi)′) into the followingEq. (4).

xp _(i) ′=scp _(i)′/(−Px)+W/2

yp _(i) ′=tcp _(i) ′/Py+H/2  (4)

[0046] where Px and Py are the pixel pitches of the CCD or the image inthe horizontal and vertical directions respectively, and W and H are thenumbers of pixels in the CCD or the image, which are aligned in thehorizontal and vertical directions, respectively.

[0047] In Step S203, a merit function Φ is calculated in order todetermine whether the approximately given exterior orientationparameters (X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and innerorientation parameters(f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)) areappropriate. For example, the merit function Φ is determined by thefollowing Eq. (5). $\begin{matrix}{\Phi = {\sum\limits_{i = 1}^{11}\quad \left\{ {\left( {{xp}_{i}^{\prime} - {xp}_{Gi}^{\prime}} \right)^{2} + \left( {{yp}_{i}^{\prime} - {yp}_{Gi}^{\prime}} \right)^{2}} \right\}}} & (5)\end{matrix}$

[0048] Namely, in the present embodiment, the merit function Φcorresponds to the total amount of squared distances between the imagecoordinates (xp_(i)′,yp_(i)′) of image points P_(i)′ corresponding tothe control points P_(i) (which are selected in the schematic image),and the approximate image coordinates (xp_(Gi)′,yp_(Gi)′) of the imagepoints P_(i)′ calculated from the surveying coordinates(Xp_(i),Yp_(i),Zp_(i)) of the control points P_(i), the approximatelygiven exterior orientation parameters(X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and inner orientationparameters (f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)).

[0049] Then, whether the merit function is smaller than a predeterminedvalue is determined, in Step S204. That is, whether the approximateimage coordinates (xp_(Gi)′,yp_(Gi)′) of the image points P_(i)′, whichare obtained from the approximately given exterior orientationparameters (X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and innerorientation parameters(f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)), aresufficiently close to the image coordinates (xp_(i)′,yp_(i)′) of theimage points P_(i)′ corresponding to the control points P_(i), which aredesignated on the schematic image, is determined. When the value Φ issmaller than the predetermined value, this process is terminated and thevalues of the presently given exterior orientation parameters (X_(GO),Y_(GO), Z_(GO),ω_(G),φ_(G),κ_(G)) and inner orientation parameters(f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)) are determinedas the exterior and inner orientation parameters that represent theexterior orientation parameters (which indicate position and theinclination of the camera) and inner orientation parameters when theschematic image was captured.

[0050] On the other hand, when the value of Φ is determined to be largeror equal to the predetermined value, in Step S204, then in step S205,compensation values (δX,δY,δZ,δω,δφ,δκ,δf,δD₂,δD₄,δD₆,δN₁,δN₂,δX_(C),δY_(C)) for the approximately given exterior orientation parameters(X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and inner orientationparameters (f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)) arecalculated by using the least squares method, for example. Namely,(scp_(i)′,tcp_(i)′) of Eq. (3) are substituted for (sp_(i)′,tp_(i)′) ofEq. (2), which represents the collinearity condition. Eq. (2) is thensubjected to Taylor's expansion at the approximate exterior orientationparameters (X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and innerorientation parameters(f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)) and the higherorder terms are neglected so as to linearize the formula. Accordingly,the normal equations, for which the compensation values(δX,δY,δZ,δω,δφ,δκ) and (δf,δD₂,δD₄,δD₆,δN₁,δN₂,δX_(C),δY_(C)) areregarded as unknown values, are derived in order to obtain theappropriate compensation values (δX,δY,δZ,δω,δφ,δκ) and(δf,δD₂,δD₄,δD₆,δN₁,δN₂,δX_(C),δY_(C)).

[0051] In Step S206, the approximate exterior orientation parameters(X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and inner orientationparameters (f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)) arealtered by the compensation values (δX,δY,δZ,δω,δφ,δκ) and(δf,δD₂,δD₄,δD₆,δN₁,δN₂,δX_(C),δY_(C)) which are obtained in Step S205.That is, each of the values (X_(GO),Y_(GO),Z_(GO),ω_(G),φ_(G),κ_(G)) and(f_(G),D_(2G),D_(4G),D_(6G),N_(1G),N_(2G),X_(CG),Y_(CG)) is replaced bythe values (X_(GO)+δX,Y_(GO)+δY,Z_(GO)+δZ,ω_(G)+δω,φ_(G)+δφ,κ_(G)+δκ)and (f_(G)+δf,D_(2G)+δD₂,D_(4G)+δD₄,D_(6G)+δD_(6,N)_(1G)+δN₁,N_(2G)+δN₂,X_(CG)+δX_(C),Y_(CG)+δY_(C)) to thereby renew orcompensate the position, inclination, and inner orientation parametersof the camera. Then the process returns to Step S202, so that Steps S202through S206 are repeated until the value Φ is determined to be smallerthan the predetermined value in Step S204.

[0052] With reference to FIG. 1, FIG. 6, and FIG. 7, the automaticsurveying operation using the surveying system of the present embodimentwill be explained.

[0053]FIG. 6 schematically illustrates an example of the schematic imageindicated on the display 45. An operator operates the mouse 43 andcontrols a mouse cursor on the schematic image in order to define anarea (a surveying area) “A” that is to be surveyed. The computer 40obtains a collinear line LN_(C) that satisfies the collinear conditionof an arbitrary pixel within the surveying area “A” (e.g. the imagepoint Q₆′ corresponding to an object point Q₆), as shown in FIG. 7. Thesurveying instrument 10 scans along the collinear line LN_(C) (which iscarried out by moving the collimation axis LN_(O) of the surveyinginstrument along the collinear line LN_(C) under the condition that thecollimation axis LN_(O) intersects the collinear line LN_(C)) andobtains measurement data at a predetermined interval (e.g. points R₁-R₅)in accordance with signals from the computer 40, so that the objectpoint Q₆ is searched with reference to the measurement coordinate valuesobtained when sighting the surveying instrument 10 to each of the pointsR_(j) (j=1, 2, . . . , 6). This operation may be carried out for allpixels within the surveying area “A”. Further, the surveying area “A”may be automatically divided into arbitrarily distanced grids (e.g.regular intervals) and the scanning operation may be carried out onlyfor each of the nodal points on the grids. Further, a curvature line “B”(or a segment) can also be defined and they may be automatically dividedinto arbitrary intervals (e.g. regular intervals). In the presentembodiment, both a surveying area “A” and a curvature line “B” aredetermined by an operator. An area or a line may also be divided withrespect to regular angular intervals for a surveying instrument.Further, a surveying area “A” and a curvature line “B” can be definedautomatically by an image processing executed on the schematic image.For example, an area and line may be detected with respect to anarbitrary color or luminance, or by using an edge enhancing process.

[0054] When the surveying instrument 10 is sighted to the point R₂ onthe collinear line LN_(C), a position which is measured is the objectpoint Q₂ which is outside the surveying area “A”. The image coordinates(x_(q2)′,y_(q2)′) on the schematic image, which corresponds to theobject point Q₂, is calculated by substituting the exterior orientationparameters (X_(O),Y_(O),Z_(O),ω,φ,κ) and the inner orientationparameters (f,D₂,D₄,D₆,N₁,N₂,X_(C),X_(C)) of which the values areobtained by the single photograph orientation process, and the surveyingcoordinates (X_(q2),Y_(q2),Z_(q2)) of the object point Q₂, into Eq. (1)through Eq. (4). However, the image coordinates (x_(q2)′,y_(q2)′) whichcorrespond to the measured object point Q₂ are different from the imagecoordinates (x_(q6)′,y_(q6)′) of the designated image point Q₆′since theobject point Q₂ is not equal to the object point Q₆ which corresponds tothe designated image point Q₆′.

[0055] On the other hand, the point R₆ on the collinear line LN_(C)coincides with the object point Q₆ where the collinear line LN_(C)intersects with a subject within the surveying area “A”. Namely, imagecoordinates calculated from surveying coordinates that are obtained whenthe surveying instrument 10 is sighted to the point R₆, coincide withthe image coordinates (x_(q6)′,y_(q6)′) of the designated image pointQ₆′. Consequently, automatic measurement for an object point thatcorresponds to an arbitrarily designated pixel on the schematic imagecan be achieved by carrying out surveying along a collinear linecorresponding to the arbitrarily designated pixel (a pixel within thesurveying area “A” in the present embodiment), and searching for anobject point of which the image coordinates obtained from its surveyingcoordinates substantially coincide with the image coordinates of thearbitrarily designated pixel.

[0056] With reference to FIG. 8 to FIG. 11, the automatic surveyingoperation of the present embodiment will be explained in detail.

[0057]FIG. 8 is a flowchart of the automatic surveying operationprogram. The program is executed in the CPU 41. The automatic surveyingoperation of FIG. 8 is carried out after the completion of the singlephotograph orientation process for the schematic image. Therefore, theexterior and inner orientation parameters for the digital still camera20, when the schematic image was taken, have already been obtained. InStep S301, the surveying area “A”, which is defined by an operator onthe schematic image on the monitor 45 by using the mouse 43, isreceived. Further, all pixels within the surveying area “A” are numbered(1 to N, where “N” is the total number of pixels inside the surveyingarea “A”).

[0058] In Step S302, “1” is set for a pixel number “i”, so that StepS303 through Step S306 are repeated until “i” reaches “N”. In Step S303,surveying along the collinear line that corresponds to the imagecoordinates (x_(i)′,y_(i)′) of a pixel number “i” is automaticallycarried out. Namely, the position of an object point that corresponds tothe pixel with the pixel number “i” is searched and measured bycomparison between the image coordinates corresponding to measuredsurveying coordinates and the image coordinates (x_(i)′,y_(i)′) of thepixel with the pixel number “i” (object point searching process). Notethat, the detail of the object point searching process will be explainedlatter.

[0059] In Step S304, the measurement data of the image coordinates(x_(i)′,y_(i)′) obtained by the object point searching process of StepS303 is recorded in the recording medium 42. In Step S305, whether thepixel number “i” is larger than the total pixel number “N” isdetermined. Namely, whether the object point searching process has beencarried out for all pixels inside the surveying area “A” is determined.When it is determined that it has not, i.e. i=N, the number “i” isincremented by one in Step S306 and the process returns to Step S303. Onthe other hand, when it is determined that i=N, this automatic surveyingoperation ends.

[0060]FIG. 9 is a flowchart of the object point searching process thatis executed in Step S303. In Step S401, a unit collinear vector(r_(ix),r_(iy),r_(iz)) for the collinear line LNc of the imagecoordinates (x_(i)′,y_(i)′) is calculated (unit collinear vectorcalculating process). In the object point searching process, thesurveying is carried out by sighting the surveying instrument 10 tohypothetical sighting points R_(j) which are arranged on the collinearline LN_(C) at predetermined intervals. In Step S402, the distance “L”from the origin O_(C) (X_(O),Y_(O),Z_(O)) of the camera coordinatesystem to a hypothetical sighting points R_(j) on the collinear lineLN_(C) is set to the initial distance L_(a).

[0061] In Step S403, the surveying coordinates (X_(Rj),Y_(Rj),Z_(Rj)) ofthe hypothetical sighting points R_(j) are calculated from the unitcollinear vector (r_(ix),r_(iy),r_(iz)), which is obtained in Step S401,and the distance “L”, as follows.

X _(Rj) =X _(O) +r _(ix) ×L

Y _(Rj) =Y _(O) +r _(iy) ×L

Z _(Rj) =Z _(O) +r _(iz) ×L  (6)

[0062] Further, the horizontal angle θh and the altitude θp for sighingthe sighting telescope 17 to the hypothetical sighting point R_(j) areobtained by Eq. (7) and Eq. (8). $\begin{matrix}{{\theta \quad h} = \left\{ \begin{matrix}{\sin^{- 1}\left( \frac{\frac{Y_{Ri}}{\sqrt{X_{Ri}^{2} + Y_{Ri}^{2} + Z_{Ri}^{2}}}}{\cos \left( {\sin^{- 1}\frac{Z_{Ri}}{\sqrt{X_{Ri}^{2} + Y_{Ri}^{2} + Z_{Ri}^{2}}}} \right)} \right)} & \quad & \left( {X_{Ri} \geq 0} \right) \\{\pi - {\sin^{- 1}\left( \frac{\frac{Y_{Ri}}{\sqrt{X_{Ri}^{2} + Y_{Ri}^{2} + Z_{Ri}^{2}}}}{\cos \left( {\sin^{- 1}\frac{Z_{Ri}}{\sqrt{X_{Ri}^{2} + Y_{Ri}^{2} + Z_{Ri}^{2}}}} \right)} \right)}} & \quad & \left( {X_{Ri} < 0} \right)\end{matrix} \right.} & (7) \\{{\theta \quad p} = {\sin^{- 1}\left( \frac{Z_{Ri}}{\sqrt{X_{Ri}^{2} + Y_{Ri}^{2} + Z_{Ri}^{2}}} \right)}} & (8)\end{matrix}$

[0063] Note that, as described in FIG. 10, the origin of the surveyingcoordinates system is positioned at the sighting origin OS in Eq. (7)and Eq. (8). When θp=θh, the X-axis coincides with the horizontal axisLh, the Y-axis coincides with the vertical axis Lp, and the Z-axiscoincides with the collimation axis (optical axis) LN_(O). Further, atthis time, the surveying instrument 10 orients the collimation axis(optical axis) LN_(O) of the sighting telescope 17 to (θh, θp) inaccordance with signals from the computer 40.

[0064] In Step S404, the measurement or surveying is carried out for thedirection which is sighted in Step S403. According to the abovemeasurement, the surveying coordinates (X_(Qi),Y_(Qi),Z_(Qi)) for theobject point Q_(i) is calculated from the substantial measurement datafor the object point Q_(i) which corresponds to the hypotheticalsighting point R_(i). The image coordinates (x_(Qi)′,y_(Qi)′) whichcorrespond to the surveying coordinates (X_(Qi),Y_(Qi),Z_(Qi)) of theobject point Q_(i) are then calculated from the exterior orientationparameters (X_(O),Y_(O),Z_(O),ω,φ,κ) and the inner orientationparameters (f,D₂,D₄,D₆,N₁,N₂,X_(C),X_(C)), in Step S405.

[0065] In Step S406, whether the image coordinates (x_(Qi),y_(Qi)) ofthe object point Q_(i) coincide with the image coordinates(x_(i)′,y_(i)′) of the collinear line LN_(C) is determined. For example,when the distance between the image coordinates (x_(Qi)′,y_(Qi)′) andthe image coordinates (x_(i)′,y_(i)′) is within a predetermined value,it is determined that the coordinates (x_(Qi)′,y_(Qi)′) of the objectpoint Qi coincide with the image coordinates (x_(i)′,y_(i)′) of thecollinear line LN_(C). In this situation, the surveying coordinates(X_(Qi),Y_(Qi),Z_(Qi)) of the object point Q_(i), which are calculatedin Step S407, are defined as the surveying coordinates of the pixel(x_(i)′,y_(i)′) that corresponds to the pixel number “i”. Accordingly,the object point searching process for the pixel number “i” ends. On theother hand, when it is determined that the above two sets of coordinatesdo not coincide, the distance “L” is replaced by “L+ΔL” in Step S408,and the processes from Step S403 are repeated. Note that, “ΔL” is anincrement for the distance “L” and defined by regarding the requiredprecision and the surveying time.

[0066] Next, with reference to FIG. 11, the unit collinear vectorcalculating process that is carried out in Step S401 is explained. FIG.11 is a flowchart of the unit collinear vector calculating process.

[0067] In the present embodiment, a unit collinear vector is calculatedby means of the least square method. Namely, in the unit collinearvector calculating process of the present embodiment, an arbitrary unitvector (r_(Gix),r_(Giy),r_(Giz)) is given as an approximate unitcollinear vector for a pixel (x_(i)′,y_(i)′), in the first step.Therefore in Step S501, the image coordinates (x_(Gi)′,y_(Gi)′) for thesurveying coordinates (X_(O)+r_(Gix),Y_(O)+r_(Giy),Z_(O)+r_(Giz)) thatcorrespond to the end of the unit vector (r_(Gix),r_(Giy),r_(Giz)) whichextends from the origin O_(C): (X_(O),Y_(O),Z_(O)) of the cameracoordinates system, are calculated using Eq. (1) to Eq. (4) with respectto the exterior orientation parameters (X_(O),Y_(O),Z_(O),ω,φ,κ) and theinner orientation parameters (f,D₂,D₄ ,D₆,N₁,N₂,X_(C),X_(C)).

[0068] In Step S502, a merit functionΨ=(x_(i)′−x_(Gi)′)²+(y_(i)′−y_(Gi)′)² is calculated for the imagecoordinates (x_(Gi)′,y_(Gi)′) obtained in Step S501. Whether the meritfunction Ψ is smaller than a predetermined value is determined in StepS503. When it is determined that the merit function Ψ is smaller thanthe predetermined value, the unit vector (r_(Gix),r_(Giy),r_(Giz)) isdefined as the unit collinear vector (r_(ix),r_(iy),r_(iz)) of the pixelthat corresponds to the pixel number “i”, in Step S504, so that thisunit collinear vector calculating process for the pixel number “i” ends.

[0069] On the other hand, when it is determined in Step S503 that themerit function Ψ is not smaller than the predetermined value,compensation values (δr_(ix),δr_(iy),δr_(iz)) for the approximate unitvector (r_(Gix),r_(Giy),r_(Giz)) are calculated by means of the leastsquare method, in Step S505. Further, the approximate unit vector isreplaced by a new unit vector(r_(Gix)+δr_(ix),r_(Giy)+δr_(iy),r_(Giz)+δr_(iz)). The process thenreturns to Step S501, so that Step S501 to Step S505 are repeated untilthe merit function Ψ is determined to be smaller than the predeterminedvalue, in Step S503.

[0070] Note that, the volume of the surveying area is calculated fromthe measurement data of the surveying area, which is obtained from theabove automatic surveying operation. Further, the area, thecircumferential length, or the like, which relates to the surveying areacan also be calculated by surveying only the circumference of thedesignated surveying area.

[0071] As described above, according to the present embodiment, ameasurement point which is designated on a schematic image can beautomatically sighted by a surveying instrument, so that the measurementpoint can be automatically measured. Further, although it is notdepicted, when using a surveying instrument with a CCD provided inside,the sighting telescope can be more precisely sighted to a point bydesignating the point on an image captured by the CCD, which has ahigher magnification than the schematic image, after rough sighting tothe point. Further, according to the present embodiment, the surveyingoperation within a surveying area can be automatically carried out whenan operator merely defines the surveying area on the schematic image, sothat efficiency of the surveying operation can be greatly improved.

[0072] Note that, when using a lens system having a long focal length,such as a telephoto lens, distortion which is a part of the innerorientation parameters is sufficiently small, so that on some occasionsit can be neglected. Namely, the inner orientation parameters(D₂,D₄,D₆,N₁,N₂) can be neglected, so that the remaining innerorientation parameters are reduced to (f,X_(C),Y_(C)). In this case,only five control points P_(i)which are three-dimensionally arranged arerequired for obtaining the inner orientation parameters (f,X_(C),Y_(C)).Further, when the displacement of the principal point from the imagecenter, the unsymmetrical components of the distortion, and the fourthand sixth distortion components are negligible, the remaining innerorientation parameters are reduced to (f,D₂), so that the number ofcontrol points required for obtaining the inner parameters is reduced tofour. As described above, since the number of unknown inner orientationparameters is reduced, the number of control points is also reduced, sothat labor and time for the surveying can be reduced.

[0073] In the present embodiment, the digital still camera 20 isarbitrarily disposed with respect to the surveying instrument 10,however, the digital still camera 20 may be disposed at the positionwhich is optically equivalent to the sighting telescope 17 of thesurveying instrument 10, by using a camera mounting accessory equippedon the surveying instrument 10. In this case, the number of unknownexterior orientation parameters can be reduced, so that the number ofcontrol points can be reduced. Further, when a schematic image iscaptured with the digital still camera 20 placed at the position whichis optically equivalent to the sighting telescope 17 of the surveyinginstrument 10 (when the center of projection for an imaging opticalsystem of an imaging device is placed at a position that is opticallyequivalent to the sighting origin of a sighting telescope), thehorizontal angle and the vertical angle can be directly calculated fromimage coordinates, so that the process is facilitated.

[0074] In the following, an alternate embodiment when the digital stillcamera 20 is positioned at a point where it is optically equivalent tothe sighting telescope 17 is explained with reference to FIG. 12. Inthis case, X_(O), Y_(O), and Z_(O) are all equal to zero(X_(O)=Y_(O)=Z_(O)=0) for the exterior orientation parameters(X_(O),Y_(O),Z_(O),ω,φ,κ). When the y-axis and the Z-axis of the cameracoordinate system are defined as to correspond to the horizontal axis Lhand the vertical Lp of the surveying instrument, respectively, thesurveying coordinate system and the camera coordinate system can beregarded as having the same coordinate system. Therefore, when thesurveying instrument 10 is sighted onto a measurement point P_(n) on theschematic image (see FIG. 6), the image coordinates (xp_(n)′,yp_(n)′) ofthe image point P_(n)′ for the measurement point P_(n)′ can be directlyobtained from the horizontal angle θh_(n) and the vertical angle θp_(n)of the surveying instrument 10 sighted onto the measurement point P_(n),and principal distance f of the imaging lens by substituting them intothe following equations:

x _(pn) ′=f·tan(θh _(n)−θh_(O))/Px+W/2,

y _(pn) ′=f·tan(θp _(n)−θp_(O))/Py+W/2  (9)

[0075] where θh_(O) and θp_(O) are initial sighting directions when theschematic image is captured (note that, when distortion compensation isnecessary, the inner orientation parameters are also used). Therefore,when a sighting position (xpn′,ypn′) is designated on the schematicimage, the horizontal angle θh_(n) and the altitude θp_(n) of themeasurement point P_(n) can be calculated as the inverse of Eq. (9) thatis:

θh _(n)=tan⁻¹(Px(xp _(n) ′−W/2)/f)+θh_(O)

θp _(n)=tan⁻¹(Py(yp _(n) ′−H/2)/f)+θp_(O).  (10)

[0076] Therefore, the surveying instrument can be sighted in thedirection represented by Eq. (10).

[0077]FIG. 12 is a flowchart of the surveying operation for the presentalternate embodiment.

[0078] In Step S601, correspondence between the schematic image and thesurveying coordinates is establish based on the single photographorientation process described in FIG. 2. In Step S602, a measurementpoint P_(n) is designated on the schematic image as a sighting point byusing the mouse 43 (see FIG. 6). Further, a sighting mark is indicatedon the designated point to indicate the sighting position. In Step S603,the sighting angels (θh_(n), θp_(n)) are calculated by substituting theposition P_(n)′(x_(pn)′,y_(pn)′) on the schematic image for thedesignated sighting point (measurement point P_(n)) into Eq. (10).Further, the surveying instrument is oriented in the above direction. InStep S604, the indication (color, shape, or size) of the sighting pointthat has already been sighted is changed and displayed on the schematicimage. By this, this surveying operation ends.

[0079] According to the present alternate embodiment, an operator canvisually recognize whether the sighting is finished on the schematicimage, so that the efficiency of the sighting is improved.

[0080] Further, another alternate embodiment is described, wherein asurveying operation is carried out for a sighting point which hasthree-dimensional position information, such as when a measurement pointto be sighted is given three-dimensional positional information asplanning values, such as a staking point, or when sighting a measurementpoint has already been measured in a previous surveying. Whenthree-dimensional information of a measurement point P_(n) is given, thesurveying instrument 10 can be automatically sighted by calculating thehorizontal angle θh_(n) and vertical angle θp_(n) by substituting thecoordinates (X_(n),Y_(n),Z_(n)) of the measurement point P_(n) intoR_(i) (X_(Ri),Y_(Ri),Z_(Ri)) of Eq. (7) and Eq. (8). FIG. 13 shows aflowchart of the surveying operation in this case.

[0081] In Step S701, correspondence between the schematic image and thesurveying coordinates is establish according to the single photographorientation process described in FIG. 2. In Step S702, a measurementpoint (e.g. staking point) of which the three-dimensional coordinatesare known is indicated on the schematic image. An operator defines asighting direction by designating a measurement point on the schematicimage, the point which is to be sighted, by using a pointing device,such as the mouse 43, in Step S703. In Step S704, the three-dimensionalcoordinates of the measurement point P_(n) are substituted into Eq. (7)and Eq. (8), in order to calculate the sighting angles (θh_(n),θp_(n))and to sight the surveying instrument in the direction represented bythe above sighting angles. In Step S705, the indication (color, shape,or size) of the measurement point which has already been sighted isaltered. By this, this surveying operation ends.

[0082] According to the above alternate embodiment, a similar effect asthat in the previous alternate embodiment can be obtained. Thus, thecompletion of the sighting can be visually confirmed on the schematicimage and efficiency of the surveying operation is improved. Note that,in Step S703, a mark indicating a selected measurement point may bealtered when the measurement point is designated. In the case ofsurveying a staking point and when the planning coordinate system forthe staking point is not equivalent to the surveying coordinate system,the coordinate values of the staking point in the planning coordinatesystem are transformed to the surveying coordinate system. On the otherhand, the inverse transformation can also be carried out.

[0083] In the present embodiments, the surveying instrument is orientedto the sighting point R_(i) on the collinear line LN_(C) thatcorresponds to an arbitrary designated pixel, and the image coordinates(x_(Qi)′,y_(Qi)′) on the schematic image are calculated from thesurveying coordinates (X_(Qi),Y_(Qi),Z_(Qi)) measured in the abovesighting. Further, whether the image coordinates (x_(Qi)′,y_(Qi)′)coincide with the image coordinates (x_(i)′,y_(i)′) of the arbitrarilydesignated pixel is determined. However, this may be determined bywhether the surveying coordinates (X_(Qi),Y_(Qi),Z_(Qi)) coincide withthe surveying coordinates (X_(Ri),Y_(Ri),Z_(Ri)) of the sighting pointR_(i).

[0084] Note that, although in the present embodiments, the controlpoints are arbitrarily designated on the schematic image by using apointing device, it is also possible to capture an image of a referencescale of which the dimensions are known, or reference marks at arbitrarypositions within the schematic image, and to calculate the exteriororientation parameters by regarding them as the control points. In thiscase, the points on the reference scale or the reference marks may bedesignated on the schematic image by a pointing device or the like.Further, when the reference scale or the reference marks are applied thecontrol points on the schematic image may be automatically detected bymeans of image processing.

[0085] In the present embodiments, a computer connected to a surveyinginstrument is used, however, the function of the computer may beintegrated into the surveying instrument or a digital still camera.Further, although in the present embodiments, a digital image isobtained by a digital still camera, any type of image capturing device,such as a digital video camera and the like, can be used as long as itcan finally produce a digital image.

[0086] Although the embodiments of the present invention have beendescribed herein with reference to the accompanying drawings, obviouslymany modifications and changes may be made by those skilled in this artwithout departing from the scope of the invention.

[0087] The present disclosure relates to subject matter contained inJapanese Patent Application No. 2002-190599 (filed on Jun. 28, 2002)which is expressly incorporated herein, by reference, in its entirety.

1. An automatic surveying system, comprising: a surveying device; acollinear-line calculating processor that obtains a collinear line whichsatisfies a collinear condition for an arbitrarily designated point on aschematic image of which the positional relation to said surveyingdevice is known; a sighting-direction control processor that controls asighting direction of said surveying device to move along said collinearline; an object point searching processor that searches for an objectpoint, where the position of said object point can be determined as apoint on said collinear line by measuring said sighting direction withsaid surveying device while carrying out the sighting direction controlprocess; and wherein a position obtained by said object point searchingprocessor coincides with an object point that corresponds to saiddesignated point on said schematic image.
 2. A system according to claim1, further comprising a position relation calculating processor thatcalculates said positional relation between said surveying device andsaid schematic image, and wherein said positional relation is calculatedfrom surveying information of at least three arbitrarily designatedcontrol points and the position of said control points on said schematicimage.
 3. A system according to claim 2, further comprising an inputdevice that enables a designation of a point on said schematic image,and said control points are defined by designating arbitrary points onsaid schematic image by using said input device.
 4. A system accordingto claim 1, further comprising an input device that enables adesignation of a point on said schematic image, and a point on saidschematic image, which is to be searched for in said object pointsearching processor, is arbitrarily designated on said schematic imageby using said input device.
 5. A system according to claim 4, whereinone of a line and a curvature line on said schematic image can bedefined by said input device, and the object point searching process iscarried out for a plurality of points included in one of said line andsaid curvature line.
 6. A system according to claim 4, wherein anenclosed curvature line on said schematic image can be defined by saidinput device, and the object point searching process is carried out fora plurality of points which are surrounded by said enclosed curvatureline.
 7. An automatic surveying system, comprising: a position relationcalculating processor that calculates a positional relation between acoordinate system to which measurement information of a measurementpoint refers and a schematic image of a surveying field, in which saidschematic image includes said measurement point; a correspondenceestablishing processor that establishes correspondence betweenmeasurement information of said measurement point and positioninformation of a point corresponding to said measurement point on saidschematic image, with respect to said positional relation; an inputdevice that enables a designation of a measurement point on saidschematic image; and a sighting direction control processor thatcontrols a sighting direction of a surveying device in accordance with aposition of said measurement point designated on said schematic image byusing said input device.
 8. A system according to claim 7, wherein saidschematic image is captured such that the center of projection of animaging optical system for capturing said schematic image is disposed ata position that is optically equivalent to a sighting origin of saidsurveying device, and said sighting direction control processor obtainsangular information of a sighting point, with respect to said coordinatesystem, from two-dimensional position information of said sighting pointdesignated on said schematic image by using said input device, andexterior orientation parameters of an imaging device which captured saidschematic image, and wherein said surveying device is sighted to adirection corresponding to said angular information.
 9. A systemaccording to claim 8, wherein said measurement point is indicated onsaid schematic image in accordance with three-dimensional positioninformation of said measurement point, when said surveying informationof said measurement point comprises given geographical data including astaking point, and controls the sighting operation of said surveyingdevice by regarding a measurement point, designated by said inputdevice, from a plurality of said measurement points as said sightingpoint.
 10. A system according to claim 9, wherein an indication of saidmeasurement point on said schematic image is changed when saidmeasurement point is sighted by said surveying device.
 11. A systemaccording to claim 7, wherein said sighting point is indicated on saidschematic image.
 12. A system according to claim 11, wherein anindication of said sighting point on said schematic image is changedwhen said sighting point is sighted by said surveying device.